Apparatus for the production of mineral wool



ETAL 2,626,425

APPARATUS FOR THE PRODUCTION OF MINERAL WOOL Filed April 13, 1951 Jan. 27, 1953 c. w. HAWTHORNE, JR.,

2 SHEETS-SHEET l R H mm N m M mH T TR T IWW A A WT mm 7 W} we 1953 c. w. HAWTHORNE, JR., ET AL 2,626,425

APPARATUS FOR THE PRODUCTION OF MINERAL WOOL Filed April 13, 1951 2 SHEETSSHEET 2 MOLTE/V M/NERAL 27 M/NERAL WOOL o 02 Q O Q INVENTOR. CHARLES W. HAWTHORNE, JR. CHARLES 7'. SAUERS Patented Jan. 27, 1953 UNITED STATES PATENT OFFICE Application April 13, 1951, Serial No. 220,859

:Claims.

This inventionis concerned with the'production of mineral wool and provides improved equipment for this purpose.

In one method of mineral'wool production, the molten mineral, say slag, is blasted with a jet of high pressure gas, say steam or-air. The 'slag is thus drawn into fibers and chilled to produce the wool. In another type of operation an apparatus known'as a spinning wheel is employed. This produces a superior mineral wool having a longer, stronger and more resilient fiber than that produced by the conventional blasting process. However, the spinning wheel has moving parts which tend'to wear excessively and also requires a motor. The conventional blast or jet type of equipment is, consequently, simpler and more durable and is still used even though it produces a somewhat less satisfactory product.

As described'and claimed in 'co-pending' application Serial No. 172,692, filed July8, 1950, by Charles W. Hawthorne, Jr., an improved mineral Wool can be made by blasting, if a special type of apparatus is employed. This apparatus comprises a chamber in which the wool is formed, a throat opening into the chamber for sucking'the molten mineral into the chamber and a plurality of gas passages disposed around the throat and projecting forward, all the passages being slanted sidewise in the samedirection around the throat. Jets from these'passages combine to produce a spiral 'streamwhich in turn produces a low pressure area in'the chamber immediately in front of the throat. A stream of molten slag is sucked" through the throat into the low pressure area and th'enceinto the twis-ting'gas stream where it is formed into fibers of superior quality.

As a result of our investigations We have developed further improvements in equipment for the production of mineral wool by means of a gas blast. These improvements require no moving parts and bring about an increase inthe capacity of the apparatus, coupled with further improvements in the character of the product while retaining the ruggedness and Simplicity, which represent advantages over the spinning wheel. In summary, our invention contemplates apparatus for producing mineral wool and including a chamber in which the molten mineral is blasted by jets of gas, a throat opening into the chamber for introducing a stream of the molten mineral to be blasted, and a plurality of passages arranged around the throat where it opens into the chamber for'directing the jets of gas ahead of the throat,- .the axes of the passa'ges beingrso oriented that they define and lie in a hyperboloid of revolution ahead of the throat. The gas jets thus directed produce in the chamber immediately ahead of the throat, a low' pressure zone in which the gas swirls vigorously and twists and shreds the molten mineral, as it cools, into long, fluffy, resilient threads of superior quality.

Preferably, the axisof revolution'of the hyperboloid is substantially the sameas the iongitudinal axis of the throat, so that the stream of slag being treated-as a straight run through the apparatus.

We preferto employ apparatus having at least two rows of passages arranged in two rings around the throat where it'opens into the chamber. The axes of the passages of one row or ring are so oriented that they define and lie in one hyperboloid of revolution ahead of the throat and the axes of the passages in :the other row or ring are oriented so that they define and .lie in another-hyperboloid of revolution ahead of the throat. Preferably the two hyperboloids are non-intersecting within the chamber and we prefer that all the hyperboloids have'substantially the same axis of revolution.

Improved results are obtained if :the inside ofv the chamber wall has a shape that isapproximately hyperboloid and with'substantially the same axis of revolution as the hyperboloids'defined by the axes of the jets.

These and other aspects:of-the 'invention will be understood more thoroughly in the light of the following detailed description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a longitudinal elevation, :partly in section, through a preferred form of the apparatus of our invention, provided with three rows of passages for forming steam jets thezhyperboloid developed'by the axes of one row of passages being shown;

Fig. 2 is a diagrammatical front #v'iew' of the apparatus of Fig. lshowing axes :of the passages Referring to the drawings and particularly to Fig. 1, it will be seen that the apparatus comprises an inlet pipe ID for supplying superheated steam or the like to the apparatus. This gas supply pipe is threaded into the outer wall of an annular member ll having a concentric cylindrical throat [2. A block 13 which contains the blasting chamber M of the apparatus is threaded into the annular member containing the throat. The outside rear portion of the block is cut away to provide an annular manifold chamber I6. The extreme rear of the block has an annular notch I! into which a ring I8 is fitted. This ring, the annular member and the block, enclose the manifold chamber 16 into which the steam is fed from the inlet pipe.

The blasting chamber, as viewed in Fig. 1, becomes progressively smaller in cross section from the rear toward the center and then flares outwardly, the longitudinal Wall IQ of the blasting chamber being in the approximate form of a hyperboloid of revolution.

The ring l8 contains three rows 2|, 22, 23 of passages. There are approximately 36 passageways in each row or ring of holes around the throat. Each hole projects forward into the chamber and also inwardly. Each hole is also slanted sidewise so that its axis does not intersect the axis 24 of the chamber and throat. Each passageway in each row projects forward by the same degree, projects inwardly by the same degree, and is slanted sidewise by the same degree, the result being that all of these axes shown in Fig. l and Fig. 2 for the center ring 22 of the passages define the hyperboloid 25 of revolution shown in Fig. l.

A hyperboloid of revolution is a warped surface generated by a straight line revolving about an axis that it does not intersect, while the revolving line maintains a fixed relationship to the axis. Thus the hyperboloid 25 shown in Fig. 1 may be developed by revolving any of the axes 25A of the passageways around the axis 24 of the chamber and throat. A hyperboloid of revolution may also be defined as a warped surface having three coaxial circular directrices.

The apparatus illustrated operates properly with a single ring or row of passages around the throat with their axes defining a single hyperboloid of revolution, for example, the hyperboloid of revolution 25 shown in Fig. 1. However, improved results and larger throughput are obtained by increasing the rows or rings of passages and jets to two and preferably to three.

The hyperboloids generated and defined by the axes of the three rings of passageways in the apparatus of the drawings are outlined in section in Fig. 5. In this view of the apparatus a stream 21 of molten mineral is sucked into the apparatus through the throat from the rear as a result of a low pressure zone created by the jets issuing from the three rings of passages, these jets defining respectively three hyper- .boloids of revolution 28, 25, 29 which do not intersect each other or the walls of the chamber.

The molten mineral enters the low pressure zone slope toward the center of the chamber is not critical, but extremely satisfactory results have been obtained with the ring shown in section in Figs. 1 and 5, in which the apparent slope of the passageways is approximately 45.

The apparatus of the invention is simple and rugged and easy to assemble and repair. The ring containing the blast passages is clamped in position between the annular member contaming the inlet throat and the block which contains the blast chamber. It is a simple matter to remove it by unscrewing the block from the annular member. If desired, a number of rings containing passages defining various shapes of hyperboloids may be employed and interchanged in the apparatus from time to time, when it is desired to change the character of the rock wool being produced.

Referring particularly to rig. 2, it will be observed that the axes of the outside ring 28 of the passages are shown in the sector 30 or the diagram, the axes of the middle ring 22 of passageways being shown in the sector 3| oi the diagram and those of the inner row 2| of passageways being shown in the sector 33 of the diagram. In the particular instances illustrated the innermost hyperboloid has a minimum diameter of about one-half inch at the neck, the middle hyperboloid a minimum diameter of about riveeighths inch and the outer hyperboloid a minimum diameter of about three-fourths inch.

The results obtained with the particular apparatus illustrated have been excellent both from the standpoint of quality and quantity.

In operation, superheated steam is introduced into the apparatus at a temperature of about 425 F. and a pressure of about pounds per square inch gauge. Steam escapes as small separate jets through the numerous passageways in the ring and the jets define the three hyperboloids, one within the other, as already described. The hyperboloids form a spiralling gas stream which first contacts and then expands.

A stream of molten slag having a temperature in the range of 2350 F. to 2500 F. is permitted to fall toward the rear of the apparatus where, due to the suction developed in the throat, it is diverted and sucked into the blast chamber as indicated in Fig. 5. When the slag strikes the spiralling stream of steam it is twisted, shredded and chilled to form an expanding stream of fibrous mineral wool which is ejected from the front of the blast chamber.

We claim:

1. In apparatus for producing mineral wool by blasting a stream of molten mineral in a gas stream, the combination which comprises a chamber in which the blasting occurs, a throat opening into the chamber for introducing the stream of molten mineral to be blasted, and a plurality of passages arranged around the throat where it opens into the chamber for directing streams of gas into the chamber ahead of the throat, the axes of the passages being so oriented that they converge forward and lie in a hyperboloid of revolution ahead of the throat.

2. In apparatus for producing mineral wool by blasting a stream of molten mineral in a gas stream, the combination which comprises a chamber in which the blasting occurs, a throat opening into the chamber for introducing the stream of molten mineral to be blasted, and a plurality of passages arranged around the throat where it opens into the chamber for directing streams of gas into the chamber ahead of the throat, the axes of the passages being so oriented that they converge forward and lie in a hyperboloid of revolution ahead of the throat and the axis of revolution of the hyperboloid being substantially the same as the longitudinal axis of the throat.

3. In apparatus for producing mineral wool by blasting a stream of molten mineral in a gas stream, the combination which comprises a chamber in which the blasting occurs, a throat opening into the chamber for introducing the stream of molten mineral to be blasted, and at least two rows of passages arranged around the throat where it opens into the chamber for directing streams of gas into the chamber ahead of the throat, the axes of the passages of one row being so oriented that they define and lie in a hyperboloid of revolution ahead of the throat, and the axes of the passages of the other row being so oriented that they define and lie in another hyperboloid of revolution ahead of the throat.

4. Apparatus according to claim 3 in which the two hyperboloids are non-intersecting within the chamber.

5. Apparatus according to claim 3 in which the two hyperboloids have substantially the same axis of revolution.

6. In apparatus for producing mineral wool by blasting a stream of molten mineral in a, gas stream, the combination which comprises a chamber in which the blasting occurs, a throat opening into the chamber for introducing the stream of molten mineral to be blasted, and a plurality of passages arranged around the throat where it opens into the chamber for directing streams of as into the chamber ahead of the throat, the axes of the passages being so oriented that they converge forward and lie in a first hyperboloid of revolution ahead of the throat, and the inside of the chamber Wall having a shape that is approximately a second hyperboloid having Substantially the same axis of revolution as the first.

7. In apparatus for producing mineral wool by blasting a stream of molten mineral in a gas stream, the combination which comprises a block defining a chamber open at both ends in which the blasting occurs, an annular member having a throat opening into the chamber at one end for introducing the stream of molten mineral to be blasted, a plurality of passages arranged around the throat where it opens into the chamber for directing streams of gas into the chamber ahead of the throat, the axes of the passages being so oriented that they converge forward and lie in a hyperboloid of revolution ahead of the throat, and an annular manifold chamber connected to the passages and disposed around the throat between the block and the member.

8. In apparatus for producing mineral wool by blasting a stream of molten mineral in a gas stream, the combination which comprises a block containing a chamber open at both ends in which the blasting occurs, an annular member con- -taining a throat opening into the chamber through an end for introducing the stream of molten mineral to be blasted, a ring containing a plurality of passages arranged around the throat where it opens into the chamber for directing streams of gas into the chamber ahead of the throat, the axes of the passages being so oriented that they define and lie in a hyperboloid of revolution ahead of the throat, and an annular manifold chamber connected to the passages at the rear of the ring and defined by the block, the annular member and the ring.

9. Apparatus according to claim 8 in which the block and the annular member are fastened together with a threaded connection.

10. Apparatus according to claim 8 in which the block and the annular member are threaded to gether and clamp the ring between them.

CHARLES W. HAWTHORNE, JR. CHARLES T. SAUERS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,627,982 Maguet May 10, 1927 2,152,423 Von Reis Mar. 28, 19-39 FOREIGN PATENTS Number Country Date 559,049 Great Britain Feb. 2, 1944 

